National Geographic made precise maps on how Earth would look in the case all the planet's ice melted. The bad news: New York, San Francisco, New Orleans, London and other cool cities would be completely gone. The good news: the entire state of Florida would disappear.

But that's the only good news. The rest is all bad: on top of the initial massive economic loss, a coastline change like this would provoke unprecedented population migrations across continents, which in turn would generate damage of apocalyptical proportions—pestilence, war, famine, and death would ensue across the globe.

Take a look at the entire Chinese and Indian coastlines—the most densely populated areas in the world.

The mountainous Japan looks almost intact, but most of its cities will be gone. The situation in Europe would be equally catastrophic: